Crimpable composite polycarbonamide filament

ABSTRACT

AN IMPROVED COMPOSITE FILAMENT COMPRISING POLYAMIDE COMPONENTS OF DIFFERENT COMPOSITION AND SHRINKAGE CHARACTERISTICS THE COMPONENTS BEING COMPRISED OF AT LEAST 50 MOLE PERCENT OF REPEATING UNITS OF THE FORMULA   -NH-(CYCLOHEX-1,4-YLENE)-CH2-(CYCLOHEX-1,4-YLENE)-NH-CO-   (CH2)Y-CO-   WHEREIN Y IS AN INTEGER IN THE RANGE OF 8-10 INCLUSIVE, THE FILAMENTS ARE FORMED BY EXTRUDING THESE COMPONENTS IN MOLTEN FORM, QUENCHING THE EXTRUDED FILAMENTS AND THEN DRAWING THE FILAMENTS. THE FILAMENTS HAVE A UNIQUE RESPONSE TO AFTER TREATMENTS (E.G. DRY HEAT) USED IN THE MANUFACTURE OF TEXTILE PRODUCTS SUCH AS CARPETS.

June 18, 1974 S H R l N KAGE E. H. OLSON ETAL CRIMPABLE COMPOSITE POLYCARBONAMIDE FILAMENT Filed Sept. 25, 1972 I50 I70 I90 TEMPERATURE c United States Patent O 3,817,823 CRIMPABLE COMPOSITE POLYCARBONAMIDE FILAMENT ABSTRACT OF THE DISCLOSURE An improved composite filament comprising polyamide components of difierent composition and shrinkage characteristics, the components being comprised of at least 50 mole percent of repeating units of the formula wherein y is an integer in the range of 8-10, inclusive. 'Ihe filaments are formed by extruding these components in molten form, quenching the extruded filaments and then drawing the filaments. The filaments have a unique response to after-treatments (e.g., dry heat) used in the manufacture of textile products such as carpets.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of our application Ser. No. 82,579, filed Oct. 21, 1970, and now abandoned which in turn is a continuation-in-part of application Ser. No. 775,678, filed Nov. 14, 1968, and now abandoned.

This invention relates to improved composite filaments and to a process for the production of such filaments.

BACKGROUND OF THE INVENTION Composite filaments are well known. Such filaments usually consist of at least two different longitudinally extending components which are arranged in eccentric man- 6 net with respect to the filament axis so that the diflering shrinkage propensities of the components result in the 3,817,823 Patented June 18, 1974 ice formation of a crimped fiber when the filament is appropriately treated, e.g., with hot water. Such filaments are produced by extruding the components in a side-by-side or sheath-core relationship.

In most cases, the composite filaments are maintained in a straight or substantially straight configuration until they are processed into a fabric, the fabric then being subjected to heat treatment to crimp the filaments and thereby produce a certain degree of bulkiness which enhances the covering power and aesthetics of the fabric.

Crimped continuous filaments and staple fibers are also produced by mechanical crimping or by passing continuous filaments under low tension through a zone of fluid turbulence at elevated temperatures. While these techniques produce crimped fibers in a satisfactory manner, advances in fabric design make it desirable to have crimped or crimpable filaments which respond to fabric after-treatments in a unique fashion.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an improved composite filament and a process for its production. Another object is to provide composite filaments which have a unique response to after-treatments used in the manufacture of textile products such as carpets, fabrics, etc. Other objects will become apparent from the examples and description to follow.

SUMMARY OF THE INVENTION The filaments of this invention are crimpable composite filaments comprising at least two continuous adherent longitudinally extending eccentrically positioned polyamide components of different composition and shrinkage characteristics, the components being composed of at least 50 mole percent of at least one type of repeating unit of the formula:

i ii if where y is an integer in the range 8-10, inclusive. S indicates a saturated ring. At least about 40 weight percent of the diamino constituent, i.e.,

MOO

of formula (I) should be of the trans-trans stereoisomeric configuration, i.e., a trans-trans diamino constituent isomer content of about 40 Weight percent based upon the weight of the diamino constituent and at least one of the components is a copolymer. Preferably the filaments consist of two components.

In one embodiment of the invention, one component consists essentially of the repeating units of formula (I), while the second component is comprised of a copolyamide containing 50-95 mole percent of the repeating units of formula (I). Preferably, the copolyamide contains -50 mole percent of polyamide units prepared from the same diamine as employed for the formula (I) units and another dibasic acid. For optimum results, the copolyamide contains 75-95 mole percent of the units of formula (I) and 5-25 mole percent of the different polyamide units.

In another embodiment, at least one, preferably at least two, of the components are comprised of copolymers containing at least 50 mole percent of repeating units of formula (I), the polymers being identical except that (1) one polymer contains at least 5 mole percent more of the repeating units of formula (I) than the second polymer or (2) one polymer contains at least weight percent more of the diamino constituent in the trans-trans stereoisomeric configuration, than the second polymer (i.e., at least a 10 weight percent greater content of the trans-trans diamino constituent isomer).

The process of this invention comprises extruding the molten components of the compositions previously described, to form the composite filament, quenching the extruded filaments to solidify the polymers and then drawing (preferably about 1.2 to 3X) the filaments. The drawing may be carried out without added heat or at elevated temperatures, e.g., above 100 C.

The components may be extruded in a side-by-side or sheath-core relation. When maximum bulk is desired, multifilament yarns from the filaments of this invention are passed through a zone where the filaments are exposed to a turbulent gaseous atmosphere at elevated temperature under low tension. This insures that the crimps in the various filaments are out of phase with respect to one another.

DRAWING The drawing illustrates graphically the shrinkages at various temperatures of yarns prepared from various polymer compositions which may be employed as components in the bicomponent filaments of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS wherein y is an integer in the range of 8 to 10. These acids include decanedioic acid (y=8), undecanedioic acid (y=9) and dodecanedioic acid (y=10).

The dicarboxylic acids are reacted with diamines of the formula:

The diamine of formula (III) and in the recurring units of formula (I) can exist in various stereoisomeric or geometric configuration, having trans-trans (tt), cis-cis (cc), and cis-trans (ct) configurations. It is necessary, for the purposes of this invention, that at least 40 weight percent of the diamine constituent be in the trans-trans configuration; at least 55 weight percent trans-trans is preferred. This minimum is generally necessary in order to achieve the desired shrinkage level as well as other filament properties.

The preferred copolyamides for use as one component of the filaments of this invention are those consisting of at least 50 mole percent of the repeating units of formula (I) and another polyamide unit prepared from the same diamine of formula (III) and a different dicarboxylic acid or a lactam such as caprolactam. Suitable dicarboxylic acids include alpha, omega aliphatic acids of 10-12 carbon atoms; aromatic acids such as terephthalic acid, isophthalic acid, paraphenylene-diacetic acid, bibenzoic acid, and 2-methyl terephthalic acid. These preferred copolyamide compositions are comprised of at least one type of recurring unit of formula (I), above, and from about 5 to 50 mole percent of at least one other type of recurring polyamide unit.

As is obvious to one skilled in the art, the above homopolymers and copolymers can be prepared from the corresponding amide-forming derivatives of the aforesaid acids (e.g., esters or acid chlorides).

The composite filaments of this invention are illustrated with filaments containing substantially equal amounts of the two components, i.e., bicomponent filaments with the components in a 50:50 weight ratio. If desired, however, this ratio may be varied considerably in order to vary the crimp frequency and dimensions or for other reasons. Preferably the relative weights of the components will be held in the range of 30:70-70:30. Some variation in the ratio among the various filaments of multifilament yarns is frequently desirable, however, since this tends to cause the crimps in each filament to be out of phase with respect to the crimps in neighboring filaments in the same yarn, thus producing a bulkier yarn. Such variations tend to occur to some extent in many bicomponent processes, e.g., a process of the type illustrated herein, since some fluctuation in the component ratio will occur even though the ratio is nominally constant.

If desired, the relative viscosity or molecular weight of the polymer in the component having the higher shrinkage is higher than that of the polymer in a second component in order to obtain a high crimp recovery when the yarn is stressed.

It is generally preferred that the filament components have a difierence in shrinkage greater than about 1%. However, much greater differences are obtainable, e.g., from about 4% to about 65%, and are highly preferred for many applications. While it is generally preferable as a practical matter to combine a homopolymer and a copolymer, it is possible, as can be seen from the drawing, to combine two copolymer components to produce crimpable bicomponent filaments.

The filaments of this invention have the characteristic that they crimp when exposed to hot aqueous solutions as would be expected of a bicomponent fiber but, in addition, when these filaments are exposed to treatments at higher temperature, e.g., with hot air or steam, the shrinkage and crimp characteristics vary with the severity and nature of the treating atmosphere. The ability to respond to dry heat treatments after a hot water treatment is very important since such treatments may be employed to finish fabrics on a commercial scale in existing equipment while the use of high pressure steam treatment is frequently not practical, since control of fabric dimensions and tension is required during the heat treatment and this cannot be readily accomplished in available steaming equipment.

In addition to the above, it has been found that the ability to modify crimp dimension by application of dry heat can be important in reducing surface loops (sometimes referred to as pickiness) in knitted fabrics, especially those which are prepared in such manner as to have a soft texture. This condition is sometimes found in knitted fabrics from bicomponent crimped filaments or from filaments crimped in other ways. It has been observed, however, that the pickiness of fabrics from the yarns of this invention can be largely eliminated by passing the fabric between hot rolls so that the crimp amplitude is reduced. It would be expected that a reduction in amplitude would reduce the crimp elongation excessively with a resultant loss in fabric strength or bulk depending on the type of fabric. However, with the yarns of this invention, the crimp frequency increases as the amplitude decreases so that loss of crimp elongation is minimized or eliminated and in some cases, the crimp elongation may actually increase.

MEASUREMENTS AND TESTS Relative viscosity, as used herein, signifies the ratio of the flow time in a viscometer of a polymer solution relative to the flow time of the solvent alone. Measurements of relative viscosities given in the examples are made with 3.7 grams of polymer dissolved in 50 ml. of a 1:1 mixture of 98-100% formic acid and phenol at 25 C. unless otherwise specified.

The shrinkage values shown are obtained by boiling a skein of the yarn under a load of 1.5 mg./denier for 30 minutes, drying in room temperature air and then heating in air at the indicated temperature for 2 minutes under the same load, unless otherwise indicated. Shrinkage is calculated from the following equation:

Shrinkage perecnt=100(cd) /c where c is the length of the skein before boiling and d is the final length after boiling or after boiling and heating in air.

EXAMPLES The following examples are illustrative rather than limitative of the invention. Parts, proportions and percentages are by weight unless otherwise indicated. It should also be noted that in the examples, the amount of cis-cis isomer does not vary greatly from about 5%; thus giving the trans-trans content of any isomer mixture effectively identifies it.

6 Example 1 A homopolymer is prepared in an autoclave from an aqueous salt solution containing 50 parts water and 50 parts of the salt of bis(4-aminocyclohexyl)methane and dodecanedioic acid. The diamine consists of tt (trans-trans), 15% ct (cis-trans), and about 5% cc (ciscis) isomers.

As a viscosity stabilizer, 0.71 mole percent of acetic acid is added. The solution also contains 0.005% manganous hypophosphite, based on the weight of the salt. This solution is heated under 300 p.s.i.g. (21.4 atmospheres) pressure for 2 hours while the temperature is raised to 300 C. The pressure is then reduced to atmospheric while the temperature is raised to 315 C. over a period of minutes and the polymer held under these conditions for two hours followed by an additional hour at 320 C. It is then extruded and cut to flake in the conventional manner.

A copolymer flake is prepared in a similar fashion using diamine containing 70% of the tt isomer. The dibasic acid used in preparing the salt is a mixture of 9 parts by weight of dodecanedioic acid and one part by weight of isophthalic acid, the viscosity stabilizer is omitted, and the copolymer is held under a vacuum at the end of the cycle to achieve the desired viscosity level.

The homopolymer, having a relative viscosity of about 2.2, and the copolymer, having a relative viscosity of about 35, are melted in separate screw melters and extruded from pairs of closely adjacent orifices so that the polymer streams coalesce to form 34 bicomponent filaments containing approximately equal weights of the components. The filament cross-sections are of dog-bone shape. Prior to extrusion, the homopolymer is passed through a homogenizer where an antistatic agent, polyethylene glycol of about 20,000 molecular weight, is injected to provide a concentration of 6% by weight of the polymer. The filaments are air-quenched in the conventional manner and then converged into a yarn and wound into a package. The yarn is then drawn to a ratio of 3.0 by passing the yarn from a feed roll to and around an elongated heating element of about 3 inches in length and having small rollers at either end to facilitate passage of the yarn and then to a draw roll rotating at a peripheral speed of 458 y.p.m. The yarn is given three passes around the heating element and three passes around the draw roll and an associated separator roll. The temperature of the heating element is C. After drawing, the yarn is wound into a package in the conventional manner. The denier of the drawn yarn is about 510. Two ends of the drawn yarn are combined and passed through a hot air bulking jet of the type described in US. 3,005,251 at a temperature of 120 C. and a pressure of 80 p.s.i.g. (6.44 atmospheres to open the yarn and produce a randomly crimped yarn, i.e., the crimps in the various filaments are out of phase and do not coincide with one another on any regular basis.

The following heat treatments are carried out with 1500 denier skeins of the yarn in a relaxed state, i.e., under no load. When a skein is placed in boiling water for 15 m nutes, removed and air dried, it is found to have 9 crimps per inch based on the extended length of the yarn and the crimp elongation is 78%. When a skein is heated in air at C. for 10 minutes, the number of crimps increases to 14 while the crimp elongation decreases to 61% indicating a larger number of crimps of lower amplitude. When a skein is treated with steam at 25 p.s.i.g. for 15 minutes, the number of crimps per inch is 12 and the crimp elongation is 67% Crimp elongation is measured by determining the length (a) of a skein of the yarn in a relaxed state (zero load) and the length (h) under a load of 0.1 gram per denier. Crimp elongation is calculated from the equation,

CE=1000(ba)/a A loop-pile carpet is prepared using untreated and heatset yarns as above. The carpet is piece-dyed as above. The two yarns dye to considerably different depths giving an interesting effect and, in addition, due to the differences in crimping and shrinking characteristics, the tufts formed being sufficient to remove most of the crimp. The jet treatment produces a randomly crimped yarn, i.e., the crimps in the various filaments are out of phase.

When these yarns are removed from the package, the filaments are substantially straight with only a slight curl by the two yarns are quite different in appearance. These or crimp which contributes to a more bulky yarn than contrasts give a desirable aesthetic effect in the finished normal. When the yarns are immersed in boiling water, product. they develop additional helical crimp. Crimp elongation, Example 2, crimp frequency and amplitude values after boiling in 10 water for 30 minutes under 1.5 milligrams/denier load Following the general procedure of Example 1, ahomoand air drying at room temperature under the same polymer is prepared from bis(4-aminocyclohexyl) methload are given in Table II. Crimp frequency is the numane, containing 7% by weight of the tt isomer, and dober of crimps per inch of the crimped filament under 1.5 decanedioic acid, the polymerization conditions being adm.p.d. load. Crimp elongation is measured as in Example justed to give a polymer flake having the relative viscoSi- I except that the length (a) is determined under a load of ties shown in Table I. During polymerization, a 1.5 mg./dn. The restraining tension of 1.5 milligrams/ aqueous slurry of TiO, pigment is added in sufficient denier is used because these yarns are to be knitted into amount to provide 0.3% by weight of TiO- as a delustertricot fabrics which imposed some restraint on the yarn ant in the final polymer. Similarly, a series of copolymers thus impeding crimp formation. When other samples of is prepared as in Example 1, except the amount of iso- 20 these yarns are subjected to heated air for 2 minutes, the phthalic acid used is varied and the quantity of tt isomer crimp frequency and amplitude change are indicated in in the diamine is also varied for some of the copolymers. Table II. In contrast, Example 1 involves yarns for carpets These copolymers designated A, B, C, and D are identified Where essentially T6811 aiming force existsin Table I. Each of these copolymers is extruded to form TricOt fabrics are prepared from yarns A, B, and C in side-by-side bicomponent filaments consisting of approxithe conventional manner. It is found that these fabrics matgly equal amounts of each component The ide..bycan be finished Over a range Of scouring and heat-setting side filaments are formed extruding the homopolymer conditions permit the selection Of conditions to and copolymer f 20 pairs f closely adjacent ifi produce fabrics of a desired softness. Scouring the fabrics in the Same spinneret so that the molten polymer streams at a relatively low temperature, e.g., 50 C., permits a coalesce immediately after extrusion to form bicomponent modmjte {legree of Shnnka? and 591113 additional coil fil t The components are in a 1:1 weight rad The formation in the yarns. Add1t1onal co1l formation can be copolymers are extruded in combination with the homo obtained and controlled by the choice of heat-setting tempolymer as id tifi d in Table I by relative viscosity. The peratures and fabric restraint. Fabr c bulk developed at yams A B C and D corresponding to copolymers A, B, several temperatures is illustrated 111 Table II. Fmlsh- C, and D are air quenched and wound into packages at mg at temperatures over the range of 150 C. to 190i C. 500 in the usual manner The yarns are then drawn and restraining the fabnc to mamtam a low fabrlc weight on a draw winder; the draw ratio is designated in Table I. generally P q fabncs whlch are lower bulk and In drawing, the yams are passed Over a feed 1.011 then softness. Fmshmg at temperatures over the same temgiven one turn around a heated draw pin; then in contact Perature range under restraint produces fabncs of with a hot plate for a distance of 3 inches and then around Increased welght i a hlgher d?gree of P and Soft th d 11 Th t t d d h ness than when finished under hlgh restraint. When the e raw ro e empera ures an spee s are s own in o scouring is conducted at a hlgher temperature, e.g., 95 Table I. It should be noted that the yarns do not attain C the amount of shrinkage and coil formation is h tfimperatum of Plate because of the shoft creased resulting in a high weight fabric requiring a contact f After drawlrfgi the 20 filament Y Whlcl} f siderable amount of stretch during the heat-setting proa dcnlfl' of abmlt 30 1S Passed through a tubular l cedure to obtain a low fabric weight. On the other hand, where it is permitted to crimp and retract slightly while h p fi hil i i i hi h f bri i h or being subjected to a turbulent air stream at a pressure of mitting moderate shrinkage of the fabric can produce 75 p.s.i.g. (6.1 atmospheres) and temperatures of 140- fabric with high bulk and good softness. If excessive 150 C. 160 C. for yarn C) and then wound into a shrinkage is allowed to occur with high temperatures, package in the conventional manner, the winding tension fabric bulk and softness is decreased.

TABLE I Copolymer Percent of the Process conditions Percent of isophthalamide bis(4-aminoconstituent in Draw r011 Homocyclohexyl) the copolymer peripheral spseed Hot polymer, methane in Draw plate relative trans-trans Weight Mole Relative Draw pin Meters/ temp., viscosity configuration percent percent viscosity ratio temp., Y.p.m. min. C.

The drawing gives the shrinkage at various temperatures of several diiferent, monocomponent filaments identified The homopolymer and copolymers are prepared followthe general procedure of Example 1. Copolymer (1) is the same as copolymer D of Example 2 except that the trans,trans isomer content is 94%. copolymer (2) is iden- B of Example 2. The homopolymer (3) composition and isomer content is identical with that of the homopolymer of Example 2. Copolymer (4) is the same as (2) except that the tt isomer content is 95%. These polymers are extruded as single component filaments, the filaments air quenched and the yarn wound into packages. The yarns are then drawn substantially as described in Example 2,

the draw pin temperature being 120 C., the hot plate (229 meters/ min.) and the draw ratio 3.0x. The final A copolymer is prepared in an autoclave from an aqueous salt solution containing 50 parts water and 50 parts of the salt of bis(4-aminocyclohexyl)methane (70% tt) and a mixture of sebacic and isophthalic acids, the mixture weight (21.6 mole percent) of isophthalamide units in the final polymer. The sebacic acid used in this and subsequent examples is a technical grade acid containing 4-7% of a mixture of undecanedioic and dodecanedioic acids as an impurity. This solution is heated under 300 p.s.i.g. (21.4 atmospheres) pressure for two hours while the temperature is raised to 325 C. The pressure is then reduced to atmospheric while the temperature is raised is then held at a temperature in the range of 325-335 C. for two hours, the autoclave being flushed with nitrogen during this period. The polymer is then extruded and cut to flake in the conventional manner. The relative vis- Following the general procedure used in preparing the copolymer, two batches of homopolymer are prepared from the salt of bis(4-aminocyclohexyl)methane (70% tt) and sebacic acid. In preparing one batch, 2.5 mole percent of acetic acid is added to the salt solution while no acetic acid is added in the preparation of the other batch. The two batches of homopolymer are mixed together in equal proportions to give a polymer having a relative The homopolymer and copolymer are extruded to form 34 filaments containing approximately equal amounts of the two components as described in Example 1. The filaments are then air quenched in the conventional manner yarn is then removed from the package and drawn at a draw ratio of 1.35 by passage around a feed roll, then over a 90 C., 12-inch (30.5 cm.) hot plate and around a draw roll rotating at a higher speed than the feed roll. The yarn is given 12 passes around the feed roll and an associated separator roll and 10 passes around the draw roll and its associated separator roll. The yarn is then wound into a package at 50 ftJmin. (15.2 meters/min.).

When samples of the yarn prepared as above are boiled off, heated in hot air at various temperatures, and in steam at various temperatures, and tested as described in Example 1, the crimp characteristics vary as shown in the r r. e m m b m a w. y m m e. w. m & 2 P W 0 a f k C n 6 e .C e :d. m a m 0 m v P .1 5 d W 2 a m a n e 3 O S m e e 1 t e t Li H w m H d w h 3 C M 3 w m 4 a m 0 b H 0 h .w 0 4 W P m w c p M 9 s d m 0 a d m h f .l H x .w m m m m o u a E d e E P d m m M H m .w W a O n C m t W P a .m o d m a l m w 0 6 .m r m .m o m m w 9 d g P 5 0 e 3 e .m m e 3 S h f N W m m e g C t 0 e 0 i r. f V n a a o 0 w n O .m M. S 5 W m m f 0 n t B w d k a g m m m m o m .w b b .m U m V. C t C V m m 5 5 0 5 0 5 m m w m m w m. 4 m 5 6 6 7 m. 2 32 32 o 02: s: 3.5305 55:. a s b 0 0m 3 wmpflmawa 5 m: 2535 am an .5 2358 om 1 mad 1...:- mw fle 22w 5.6 NA Iii-t- 2: mad: wwdhad 1115......- 36 and ii: iii.- .-Efiuwg fi n fins a g Hw mm mm mm mm mm mm um mm mm. mm mm aw mm mm mm *0 am am I I 50.39 $5263 20 Ec 6 mac 0 mo 0 a: 0 me o one 0 o d m3 0 m2 0 wmo 6 m3 0 Eo 0 So 0 N3 0 m3 6 Ec 0 one 0 we 6 a: c as o I SS2 0 m b w m n b w o w b N m m c v m m m m b A a N w u o w o w o N h m o w b w o A oUflEQEmJfiWEO mu m 3 0 mm I h 2 c mm b 2 m 2 m g m 3 m Sn w mH b 2 5 am a mm mm w on m" h io cmH mm mm mm cm cc on mm mm mm 5* how on mm on E. ow mm 5 mm n fifimmflwflwvouh E on as E an S 2 2 3 2 mm a E a a m 3 NH 3 2 e583 de ance 93 can o: c2 c3 c3 c3 o: 2: co 2: c2 c5 c3 Q3 2: can c2 c5 02 03 U o E PH #4 C m :4 C m :4 C m :4 0 m a F H G O m 4 SEEQQQ E When a yarn is prepared as described above except that the draw ratio is 1.8 and the filaments contain about 38% by weight of the homopolymer component and about 62% by weight of the copolymer component, the crimp characteristics, determined as in Example 1, are as shown in Table IV below.

A homopolymer is prepared following the general procedure of Example 1 from the salt of 70 tt, bis(4-aminocyclohexyl)methane and dodecanedioic acid. The relative viscosity of the polymer is 34. A copolymer is prepared as in Example 4, except that the relative viscosity is 39. The two polymers are processed into drawn yarn as described in Example 4, except that the draw ratio is 1.8. The crimp characteristics of the final yarn, determined as in Example 1, after boiling in water and in steam and heated air, at various temperatures, are shown in the following table.

'IABLEV Environment Hi Air Steam Temp., 100 100 130 160 190 108 121 131 Crimp elongat n,

percent 163 140 138 170 121 167 174 193 Frequency:

Crimps/ineh 8.3 13.2 11.0 15.1 37.8 11.5 20.5 27.3 Crimps/c 3.3 6.2 4.3 5.9 14.9 4.5 8.1 10.8 Crimp amplitud Example 6 A homopolymer having a relative viscosity of 46 is prepared from the salt of bis(4-aminocyclohexyl) methane (70 tt) and sebacic acid following the procedure of Example 2. In a similar fashion, a copolymer is prepared from a salt solution containing 48 parts water and 52 parts of the salt of 'bis(4-aminocyclohexyl)methane and sebacic acid with the addition of sufiicient epsilon caprolactam to provide by weight (27 mole percent) of caproamide units in the final polymer. The homopolymer and copolymer are extruded to form 6 bicomponent filaments, the filaments are quenched and wound into a packagefollowing the general procedure of Example 1. The yarn is then drawn at a raw ratio of 3.0 over a 95 C. hot plate as described in Example 2, except that 8 passes around the feed roll and 10 passes around the draw roll are employed and the windup speed is 100 yds./min. (30.5 meters/min). The crimp characteristics of the final yarn, determined as in Example 1, after boiling in water, and after heating in air and steam at various temperatures, are shown in the table below.

TABLE VI Environment E0 Air Steam Temp., C 100 190 108 121 131 Crimp elongation,

percent 215 126 134 146 142 143 157 146 Frequency:

Crimps/lneh 8. 9 7. 2 8.1 11. 7 12. 8 8. 9 8. 7 9. 5 Crimps/em 3. 5 2. 8 3. 2 4. 6 5. 0 3. 5 3. 4 3. 6 Crimp amplitude:

Mils 40 50 40 30 30 40 50 50 1.0 1.3 1.0 0.8 0.8 1.0 1.3 1.3

Example 7 Following the general procedure of Example 1, a homopolymer is prepared from the salt of bis(4-aminocyclohexyl)methane (70% tt) and dodecanedioic acid, the final polymer having a relative viscosity of 28.6. In a similar fashion, a copolymer is prepared from the salt of bis(4-aminocyclohexyl)methane (70% tt) and a mixture of dodecanedioic and isophthalic acids, the mixture containing sulficient isophthalic acid to provide 10% by weight (11.7 mole percent) of isophthalamide units in the final polymer. This copolymer has a relative viscosity of 33.

The homopolymer and copolymer, in equal amounts by weight, are extruded in side-by-side relation from the same orifices of a spinneret to form 34 round, bicomponent filaments. The filaments are air quenched and converged into a yarn in the conventional manner. The yarn is cold-drawn in two stages to a draw ratio of 3.0 using power-driven rollers to aifect the drawing. From the second draw roll, the yarn is given six passes around a heated roll at C. and is then wound into a package at a speed of 1795 yds./min. (1641 meters/min). The filaments in the final yarn are of 7 denier.

Example 8 Following the general procedure of Example 1, a homopolymer is prepared from bis(4-aminocyclohexyl)methane, containing 70% by weight of the tt isomer, and dodecanedioic acid, the polymerization conditions being adjusted to give a polymer flake having a relative viscosity of 45. During polymerization, a 20% aqueous slurry of finely divided kaolinite is added in suflicient amount to provide 2.0% by weight of kaolinite as a delusterant in the final polymer. Similarly, a copolymer having a relative viscosity of 45 is prepared as in Example 1 with the addition of 2% by weight of kaolinite during polymerization. Side-by-side filaments are formed by extruding the homopolymer and copolymer from 36 orifices in the same spinneret so that the molten polymer streams coalesce immediately before extrusion to form bicomponent filaments. The components are in a 1:1 weight ratio. After extrusion the filaments are air quenched and converged into a yarn in the usual manner. The yarn is then drawn in two stages. In the first stage the yarn is drawn between two power driven rolls at a ratio of 1.26. The yarn is then passed to the second stage draw roll which has a temperature of 140 C. where it is given 9 passes around the draw roll and its associated separator roll and drawn sulficiently to give a total draw ratio of 1.6. The yarn is then wound into a package in the conventional manner. The yarn has a tenacity of 2.6 g./den., an elongation at break of 36.8% and an initial modulus of 31.2 g./den. The shrinkage after boil-off is 7.3% and the total shrinkage after boiling-off and heat-setting at C. for 3 minutes is 11.8%. After skein boil-ofl under 0.5 mg./denier load, the crimp development is 4.3% and the crimp elongation is 4.0%. When a skein of the yarn is boiled 01f, dried andheat-set at 190 C. for 3 minutes with the same load, the crimp development is 18.1% and the crimp elongation 22%.

Crimp elongation and crimp development are measured by determining the length (a) of the skein under a load 13 of 1.5 mg./denier and the length (b) under a load of 0.1 gram/ denier. Crimp elongation (CE) and crimp development (CD) are then calculated from the equations:

The yarn which has a denier of 144 is twisted 8 turns Z per inch and two yarns are plied together with 4 turns 8 per inch to give a 288 denier yarn. A twill fabric is woven using the plied yarn in both the filling and the warp. The fabric is then scoured, heat-set at 325 F. for 2 minutes, dyed and heat-set at 360 F. for 2 minutes. The finished fabric displays unique properties of stretch, liveliness and resistance to wrinkling. It can be repeatedly stretched in the warp direction and in the fill direction with complete and instantaneous recovery from the stretch.

A number of ends of the yarns are combined to form a tow and the tow is mechanically crimped in a stuffer box crimper. The tow is then cut into 4-inch (10.2 cm.) staple in the conventional manner. The staple is carded and then pin drafted to form sliver. The sliver is wet in cold water, centrifuged, and then heated at 149 C. in air for 10 minutes to dry the sliver and develop bicomponent crimp in the filaments. The sliver is spun into yarn and the yarn processed into a plain weave fabric. The fabric is scoured and dyed in the conventional manner and heat-set at 177 C. The fabric is observed to be lofty and bulky and has attractive aesthetics. When a fabric is prepared in identical fashion, except that the step of wetting and heating the sliver to develop crimp is omitted, the resulting fabric is hard and stiff.

As illustrated in the examples, the filaments and yarns of this invention exhibit a unique response to aftertreatments.

The ability to select different crimp dimensions permits a choice in the level of fabric bulk, softness, cover, loopiness and stretch in knit fabrics and pucker and crepe surface in foven fabrics. Thus, a single fiber may be employed to produce a variety of fabric effects.

The preferred filaments are those consisting of two components, since this is the simplest method of obtaining the desired results. Obviously, however, additional components may be added if desired for any reason. The components may be extruded in side-by-side or sheathcore relation. If a sheath-core filament is prepared, the core should be highly eccentric with respect to the fiber axis to provide the maximum crimp. The relative amounts of components in the filament may also be varied to achieve the optimum results.

The filaments of this invention may contain suitable heat stabilizers, antioxidants, light stabilizers, ultraviolet light absorbers, delusterants, pigments, dyes, and the like. Polymer additives may also be present to improve dyeability, soil repellence, crease resistance, hand, water repellency, wickability, strength, elongation, modulus, static propensity, or melting point of the fiber.

The filaments may be of round or nonround cross sections as desired. Nonround cross sections such as heart shape, cruciform shape, multilobal shape, shield shape or other shapes may be employed as desired.

If desired, the filaments of this invention may contain a durable antistatic agent. The antistatic agent should be present in a concentration of at least 2% by weight of the polymer and may be added to one of the components or all of the components in the filament as desired. Suitable antistatic agents include the high molecular weight poly(alkylene ethers), i.e., those in the molecular Weight range of 1300 to 200,000. Suitable antistatic agents are disclosed in British Patent 963,320.

The filaments of this invention may be used in continuous lengths as monofil or in multifilament yarns or may be cut into staple lengths if desired. In addition to their usefulness in carpets, they may be used to advantage in knitted fabrics such as hosiery and apparel fabric or in Woven fabrics.

What is claimed is:

1. Crimpable composite filament comprising two continuous adherent longitudinally extending eccentrically positioned polyamide components of different composition and shrinkage characteristics each of said components comprising at least 50 mole percent of at least one type of repeating units of the formula:

wherein y is an integer between 8 and 10, inclusive, with the proviso that at least 40 weight percent of diamino constitutents of the repeating units of said formula (I) be of a trans-trans stereoisomeric configuration, one of the components being a copolymer and one of the components being a homopolymer.

2. Filament of claim 1 wherein the copolymer component consists essentially of between about and mole percent of repeating units of said formula (I).

3. Filament of claim 2 wherein one of the said components comprises about 30 to 70 weight percent of said filament.

4. Filament of claim 4 wherein one of the said compoents comprises about 50 weight percent of said filament.

5. Filament of claim 1 wherein the trans-trans diamino constituent isomer content is at least 55 weight percent.

6. Filament of claim 1 in staple form.

References Cited UNITED STATES PATENTS 3,393,210 8/1968 Speck 260-78 R 3,03 8,235 6/ 1962 Zimmerman 161173 FOREIGN PATENTS 668,703 2/1966 Belgium. 668,704 2/ 1966 Belgium. 668,703 2/1966 Belgium. 1,488,993 6/ 1967 France.

GEORGE F. LESMES, Primary Examiner L. T. KENDELL, Assistant Examiner US. Cl. X.R. 

